Reclosable stand-up package and method of manufacturing same

ABSTRACT

A method of manufacturing is provided for a reclosable, free standing package adapted to be self-supporting in an upright position when resting on a horizontal support surface. The method includes the steps of providing a bottom panel in the form of a stand-up web having a planar base and a pair of legs depending from opposite sides of the base; inserting the stand-up web between a first film panel and a second film panel; and creating spaced apart bottom edges of the package by sealing a lower end of the first film panel to one of the legs, and a lower end of the second film panel to the other of the legs such that an entire surface of the base lies substantially parallel to a plane containing the bottom edges.

FIELD OF THE INVENTION

The present invention relates broadly to reclosable packages and methodsof forming such packages, and more particularly, pertains to reclosablepackages manufactured on form, fill and seal machines wherein thereclosable packages are self-supporting.

BACKGROUND OF THE INVENTION

Form, fill and seal technology is known in the packaging industry as amethod to package consumable goods. Consumable goods that are not usedcompletely when the package is initially opened rely on a zipper closureto reclose the package and keep the remaining contents fresh. In someapplications, a tamper-evident seal is included on the package tosignify whether access has been gained to the zipper closure. Examplesof consumable goods that are often packaged in packages with a zipperclosure include potting soil, fertilizer, pet food, dog biscuits, andmany different foods edible by humans.

For certain goods, the bottom of the reclosable package is provided witha configuration that will enable the package to stand up and beself-supporting in an upright position when resting on a horizontalsupporting surface such as a shelf, cupboard, table or the like. Furtherdevelopments in providing these types of stand-up packages with improvedstability are desirable.

SUMMARY OF THE INVENTION

It is one object of the present invention to provide an improved methodof manufacturing a reclosable, stand-up package by inserting a stand-upweb in a horizontal form, fill and seal process for making plastic bags.

It is also an object of the present invention to provide an improvedreclosable, stand-up package that has a stronger, sturdier and morestable base capable of supporting the package so that it will not tipover.

The present invention is directed to a method of manufacturing areclosable, free standing package adapted to be self-supporting in anupright position when resting on a horizontal support surface. Themethod includes the steps of providing a bottom panel in the form of astand-up web having a planar base and a pair of legs depending fromopposite ends of the base. The stand-up web is inserted between a firstfilm panel and a second film panel and a lower end of the first filmpanel is sealed to one of the legs and a lower end of the second filmpanel to the other of the legs. Thus, an entire surface of the base liessubstantially parallel to a plane containing the bottom edges.

The step of sealing the first and second film panels to the legsincludes only horizontal sealing. The method includes the step ofcreating side seams by providing seals across the first film panel andthe second film panel. The method further includes the steps ofproviding a combined zipper closure and slider device between the firstfilm panel and the second film panel, and sealing a first closureprofile of the zipper closure to the first film panel and sealing asecond closure profile of the zipper closure to the second film panel.Prior to providing a combined zipper closure and slider device betweenthe first film panel and the second film panel, the continuous film webcan be slit to create the first film panel and the second film panel.Alternatively, the web can be folded onto itself to create the first andsecond film panels. The step of providing a stand-up web includesunwinding and folding of a supply of film. The method further includesthe step of providing a tamper-evident header over the slider device toindicate whether access has been gained to the slider device. The methodalso includes the step of providing a tamper-evident membrane betweenthe first closure profile and the second closure profile. The step ofslitting the film web is preceded by the step of passing the film over aV-board. The step of providing a combined zipper closure and sliderdevice between the first film panel and the second film panel includesthe step of feeding the combined zipper closure and slider devicethrough a bottom end of the V-board. Alternatively, the step ofproviding a combined zipper closure and slider device between the firstfilm panel and the second film panel includes a step of feeding thecombined zipper closure and slider device in front of the V-board.

In another aspect of the invention, a reclosable, stand-up packageincludes first and second side panels, each having a top edge, opposedside edges and a bottom edge. The opposed side edges of the side panelsare sealed together. A zipper closure is sealed to the first and secondside panels along the top edges thereof. The zipper closure extends fromone of the sealed side edges to the other of the sealed side edges. Aslider device is operably mounted on the zipper closure for opening andclosing the zipper closure. A bottom panel has a planar base and a pairof legs depending from opposite ends thereof. The pair of legs aresealed to the bottom edges of the first and second side panels such thatthe base is raised a constant distance above the bottom edges. Thebottom panel provides a widened configuration enabling the package to beself-supporting in an upright position when the bottom edges are adaptedto rest on a horizontal support surface. The legs of the bottom panelare sealed to the bottom edges of the first and second side panels alongentire lengths of the bottom edges extending between the opposed sealedside edges. The zipper closure includes a removable internaltamper-evident membrane extending between the first and second sidepanels. The package also includes a removable tamper-evident headerconnected to the zipper closure and surrounding the slider device.

Various other objects, features and advantages of the invention will bemade apparent from the following description taken together with thedrawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The drawings illustrate the best mode presently contemplated of carryingout the invention.

FIG. 1 is a perspective view of a flexible, reclosable stand-up packagewith a tamper-evident header attached thereto;

FIG. 2 is a schematic, sectional view of a folding step used in formingthe flexible, reclosable stand-up package;

FIG. 3 is a schematic, sectional view of a slitting step used in formingthe flexible, reclosable stand-up package;

FIG. 4 is a schematic, sectional view of the insertion of a combinedslider device and zipper closure during the formation of the flexible,reclosable stand-up package;

FIG. 5 is a schematic, sectional view of the insertion of a stand-up webused in forming the flexible, reclosable stand-up package;

FIG. 6 is a schematic, sectional view of a filling operation, and thecreation of a tamper-proof header used in forming the flexible,reclosable stand-up package;

FIG. 7 is a schematic, sectional view of a sealing operation for thestand-up web used in forming the flexible, reclosable stand-up package;

FIG. 8 is a schematic, sectional view of the locating of score lines inthe tamper-proof header used in forming the flexible, reclosablestand-up package;

FIG. 9 is a schematic, sectional view of the removal of the tamper-proofheader from the flexible, reclosable stand-up package;

FIG. 10 is a perspective view of the finished, flexible, reclosablestand-up package with the tamper-proof header removed;

FIG. 11 is a schematic, perspective view of a horizontal form, fill andseal machine for manufacturing the flexible, reclosable stand-uppackage; and

FIG. 12 is a schematic view similar to FIG. 11 but showing analternative location for feeding the combined slider device and zipperclosure in the form, fill and seal machine.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The addition of a stand-up web to a flexible package, such as a bag, isadvantageous in enabling the package to be self-supporting withouttipping over. The process described herein installs a stand-up web tobags manufactured using form, fill and seal machines.

A flexible, reclosable package or bag 10 having side panels 12, 14 and araised bottom panel 16 is shown in FIG. 1. Side panels 12, 14 are sealedtogether at side seams 18, 20, and sealed at lower ends with a pair ofbottom edges 22, 24 on bottom panel 16. A zipper closure arrangementhaving mating profiles to open (unseal and reseal) the bag 10 is shownat 26. The zipper closure 26 can include a variety of configurations andstructures. The zipper closure 26 includes a first mating profile 28(FIG. 4) and a second mating profile 30 (FIG. 4) that engage anddisengage, as appropriate, to open and close the bag 10. Zipper closure26 extends from a first edge 32 of the bag 10 to a second edge 34 acrossa mouth 36. First and second profiles 28, 30 have respective first andsecond flanges 38, 40 depending therefrom which are sealed to inner,upper surfaces of the side panels 12, 14 as seen in FIG. 9. The ends ofthe flanges 38, 40 include an internal tamper-evident membrane 42 thatlies within the interior of bag 10. In order to gain access to theinterior of the bag 10, the tamper-evident membrane 42 needs to beruptured. Membrane 42 can be integrally formed with flanges 38, 40 whenzipper closure 26 is extruded or can be applied after the matingprofiles have been formed.

A slider device 44 is mounted on zipper closure 26 to facilitate openingand closing zipper closure 26. Slider devices and how they function toopen and close zipper closures in general are taught in U.S. Pat. Nos.5,063,644; 5,301,394 and 5,664,220, each of which is incorporated byreference herein. A notch (not shown) is disposed within zipper closure26 adjacent to edge 34 in the bag 10. The notch is designed to provide a“park place” into which slider device 44 settles when zipper closure 26is sealed and slider device 44 is at the first edge 32. Such notchdecreases any tendency for an incomplete interlock between first matingprofile 28 and second mating profile 30.

FIG. 1 illustrates an external tamper-proof or tamper-evident header 46disposed over slider device 44. By “tamper-evident”, it is meant that itprovides an indication to the consumer as to whether the package 10 hasbeen previously opened. In this embodiment, the tamper-proof header 46covers and forms a complete enclosure around the zipper closure 26 andslider device 44. Tamper-evident header 46 is formed by sealing the topsof side panels 12, 14 over slider device 44 as further depicted in FIGS.6, 7 and 8. In order to access the interior of package 10 and sliderdevice 44 for the first time, the tamper-evident header 46 needs to beremoved as shown in FIG. 10. Various tamper-evident structures are knownthroughout the art of resealable packaging and may be used in lieu oftamper-evident header 46.

The bag 10 described and shown in FIG. 1 can be manufactured by ahorizontal form, fill and seal machine 48 generally of the type setforth in U.S. Pat. No. 6,293,896 herein incorporated by reference. Thebag 10, whether with or without the tamper-evident membrane 42 and thetamper-evident header 46, is manufactured, filled and sealed by a singleprocess that includes sequential steps. The zipper closure 26, sliderdevice 44 and any tamper-evident structure are applied to the bag 10prior to the bag 10 being filled with items.

Referring now to FIG. 11, the horizontal form, fill and seal machine 48includes a process line that progresses from right to left such that,the final fill bag 10 is at the left of the Figure. The package or bag10 is manufactured upside down so that filling takes place through thebottom of the bag 10.

The web 50, which will provide side panels 12, 14, is supplied on aroll. In an alternative embodiment, the web 50 may comprise one or morelayers of film. A series of tensioners 52 helps to control tension onthe web 50 during the bag making process. From the tensioners 52, theweb 50 progresses to a V-board 54 where the web 50 is folded as depictedin FIG. 2. In the first embodiment of the invention, a slitter knife 56close to the face of V-board 54 slits web 50 into two panels or halvesof web 58, 60. Alternatively, as shown in FIG. 12, the slitter knife canbe eliminated and the web 50 simply folded to create the side panels 58,60.

An extended length of zipper closure 26 is provided via spool 62simultaneously with the feeding of film 50. The “home” notches discussedabove are punched into zipper closure 26 at an interval defined by thebag width by an in-line punch 64 that may be a die, stamp, knife orother such process. Each notch is formed in the profile of zipperclosure 26 before the zipper closure 26 is incorporated into the bag 10.Slider device 44 is provided from a rotating bowl 66 having a deliveryconduit 68 which delivers a series of properly-oriented slider devices44 to an applicator 70. The applicator 70 combines the zipper closure 26with slider device 44 so that the slider device 44 is parked in thenotch punched in the zipper disclosure 26. If misaligned on the zipperclosure 26 or notch, the slider device 44 can be phased into registerwith the notch by sliding or moving the slider device 44 along zipperprofile by guides or the like, until the slider device 44 is in registerwith the bag parked position or notch.

The zipper closure 26 with the slider device 44 is fed through a slot orthe like at the base of the V-board 54 in between the two film halves58, 60 of web 50 as represented in FIG. 4 with profiles 28, 30 beingseparated. With this arrangement, the combined zipper closure 26 andslider device 44 is allowed to travel in a straight line from the pointwhere slider device 44 is applied to zipper closure 26 to a point wherethe combined zipper closure 26 and slider device 44 are attached to thefilm halves 58, 60. Preferably, once attached to the film halves 58, 60,a straight line of travel, with no bends or turns, is maintained.

It is to be noted that because the bag 10 is manufactured upside down(i.e. the top of the bag 10 is at the bottom of the process line), thezipper closure 26 with the slider device 44 is positioned at the bottomof the film halves 58, 60 during bag formation.

After the film halves 58, 60 pass between a pair of vertical rolls 71, afilm from a roll 72 is folded at 73 (FIG. 11) to provide a stand-up,three sided web 74. The stand-up web 74 is positioned and held betweenthe lower portions of the film halves 58, 60 as illustrated in FIG. 5.The stand-up web 74 includes a planar base 76 and a pair of depending,diverging legs 78, 80 of equal length, and serves to define the raisedbottom panel 16 of the finished bag 10. As will be appreciatedhereafter, the stand-up web 74 is sized to provide a widenedconfiguration at the bottom of finished bag 10 in order to enable thebag 10 to be self-supporting with a better stability than prior artstand-up packages.

After the introduction of the stand-web 74, heated seal bars 82 providevertical seals on the film and zipper closure combination. Thesevertical seals will eventually result in side seams 18, 20 of package orbag 10 in FIG. 1. Side seams 18, 20 extend along the entire height ofbag 10. Typically, each seal bar 82 has a pair of bars on opposite sidesof the film. Heat may be provided on one or both sides.

A top seal bar 84, positioned at the bottom of the process line, sealsthe zipper closure 26 to the film halves 58, 60 and can further be usedto provide sealing of the tamper-evident header 46. The tamper-evidentstructure 46 provides an indication to the consumer whether bag 10 hasbeen previously opened. In order to gain access to the interior of bag10, the tamper-evident header 46 needs to be penetrated. Top seal bar 84has first sealing surfaces positioned to provide pressure and typicallyheat to the area where the flanges 38, 40 of zipper closure 26 meets thefilm halves 58, 60 to form seals 86, 88 (FIGS. 6-9). The top seal bar 84also has second surfaces positioned to provide pressure and to typicallyheat an area below slider device 44 in FIG. 6 and form a seal betweenfilm halves 58, 60 at a topmost, horizontal seals 90.

FIG. 6 represents a sectional view of the bag formation process afterthe seals 86, 88 and 90 have been made, and the bag being formed arrivesat a filling station 92 (FIG. 11) downstream of seal bar 84. At thefilling station 92, items or materials 94 (e.g. cereal, snack food,fertilizer, etc.) to be contained in the resulting package are deliveredby hopper 96. Hopper 96 includes valves, gates and doors, as needed, todeposit an appropriate amount of item 94 into the package from thebottom thereof while the stand-up web 74 is held away from the hopper 96and the item or material flow.

A bottom seal bar 98 located at the top of machine 48 is used to heatseal the base 76 and provide seals 100, 102 between legs 78, 80 of thestand-up web 74 and the bottom edges of the film halves 58, 60 asdepicted in FIG. 7. Seals 100, 102 extend across the entire length ofthe bottom edges from side seam 18 to side seam 20. As a result, base 76forms a raised bottom wall for the finished package 10. It will beunderstood that the size of the stand-up web 74 and, particularly itswidth, will dictate the degree of widened configuration at the bottom ofthe package which will make the bag 10 more stable and prevent tippingover as it sits on a horizontal support surface. In FIGS. 5-9, theheight of the legs 78, 80 is shown exaggerated for clarity only and itshould be appreciated that the base 76 usually sits much closer to thesurface on which bag 10 is supported, as shown in FIGS. 1 and 10. It isto be noted that the entire base 76 will be spaced above a supportsurface over a constant distance defined by the equal height of the legs78, 80. In other words, the raised bottom panel 16 lies generallyparallel to a plane defined by the bottom edges 22, 24.

Bottom seal bar 98 may include an adjustable depth perforator forproviding perforations 104 (FIG. 8) in the film between the area of thezipper closure/film seams 86, 88 and the seam 90 at the top of the filmhalves 58, 60. These perforations or score lines 104 allow easy removalof the tamper-evident header 46 by the consumer. Preferably, theperforations 104 or other weakened area are positioned close to the areawhere the zipper flanges 38, 40 are sealed to the film halves 58, 60.This is done to minimize the amount of film remaining close to theslider device 44 after the tamper-evident header 46 is removed from bag10 as illustrated in FIG. 9.

A vertically oriented blade or cutter bar 106 cuts the edges at the sideseams 18, 20 to provide individual, filled, free standing packages 108.

FIG. 12 depicts an alternative form, fill and seal machine 48 identicalto that disclosed above except that zipper closure spool 62, in-linepunch 64, slider bowl 66, delivery conduit 68 and zipper closure andslider device applicator 70 are located above the process line ratherthan beneath it. In this design, the combined zipper closure and sliderdevice is fed in front of the V-board 54 for insertion between filmhalves 58, 60. As shown in FIG. 12, the V-board 54 does not include aslitter such that the web 50 maintains its integrity and is folded tocreate the side panels 58, 60.

It should now be appreciated that either process machine 48 provides aflexible, reclosable stand-up bag 10 with a removable tamper-evidentheader 46 as shown in FIG. 1, as well as an internal tamper-proofmembrane 42 as seen in FIG. 9. The insertion of stand-up web 74 enablesthe bag 10 to have a widened lower configuration with a raised bottompanel 16 so that the bag is self-supporting with enhanced stability. Thestand-up web 74 can be made from a stiffer material than film panels 58,60 and could be made from a transparent material that would allow theconsumer to view the contents of the bag 10. In addition, the stand-upweb 74 may include a material that has a high amount of metalizing whichwould give the package even greater stability.

Having described the presently preferred embodiments, it is to beunderstood that the invention may be otherwise embodied within the scopeof the appended claims.

1. A method of manufacturing a reclosable, free standing package adaptedto be self-supporting in an upright position when resting on ahorizontal support surface, the method comprising the steps of: a)providing a bottom panel in the form of a stand-up web having a planarbase and a pair of legs depending from opposite ends of the base; b)inserting the stand-up web between a first film panel and a second filmpanel; and c) creating spaced apart bottom edges of the package bysealing a lower end of the first film panel to one of the legs, and alower end of the second film panel to the other of the legs such that anentire surface of the base lies substantially parallel to a planecontaining the bottom edges.
 2. The method of claim 1, wherein the stepof sealing the first and second film panels to the legs includes onlyhorizontal sealing.
 3. The method of claim 1, including the step ofcreating side seams by providing seals across the first film panel andthe second film panel.
 4. The method of claim 1, including the steps ofa) providing a combined zipper closure and slider device between thefirst film panel and the second film panel; and b) sealing a firstclosure profile of the zipper closure to the first film panel andsealing a second closure profile of the zipper closure to the secondfilm panel.
 5. The method of claim 4, wherein prior to the step ofproviding a combined zipper closure and slider device between the firstfilm panel and the second film panel, the method comprises the step of:a) slitting a film web to provide the first film panel and the secondfilm panel.
 6. The method of claim 1, wherein the step of providing astand-up web includes unwinding and folding a film.
 7. The method ofclaim 4, including the step of providing a tamper-evident header overthe slider device to indicate whether access has been gained to theslider device.
 8. The method of claim 4, including the step of providinga tamper-evident membrane between the first closure profile and thesecond closure profile.
 9. A reclosable free standing package made bythe method according to claim
 1. 10. The method of claim 5, wherein thestep of slitting the film web is preceded by the step of passing thefilm web over a V-board.
 11. The method of claim 10, wherein the step ofproviding a combined zipper closure and slider device between the firstfilm panel and the second film panel includes the step of feeding thecombined zipper closure and slider device through a bottom end of theV-board.
 12. The method of claim 10, wherein the step of providing acombined zipper closure and slider device between the first film paneland the second film panel includes a step of feeding the combined zipperclosure and slider device in front of the V-board. 13-16. (canceled)